What's Old Is New in the Large Magellanic Cloud

This vibrant image from NASA's Spitzer Space Telescope shows the
Large Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy.

The
infrared image, a mosaic of 300,000 individual tiles, offers
astronomers a unique chance to study the lifecycle of stars and dust in
a single galaxy. Nearly one million objects are revealed for the first
time in this Spitzer view, which represents about a 1,000-fold
improvement in sensitivity over previous space-based missions. Most of
the new objects are dusty stars of various ages populating the Large
Magellanic Cloud; the rest are thought to be background galaxies.

The
blue color in the picture, seen most prominently in the central bar,
represents starlight from older stars. The chaotic, bright regions
outside this bar are filled with hot, massive stars buried in thick
blankets of dust. The red color around these bright regions is from
dust heated by stars, while the red dots scattered throughout the
picture are either dusty, old stars or more distant galaxies. The
greenish clouds contain cooler interstellar gas and molecular-sized
dust grains illuminated by ambient starlight.

Astronomers say
this image allows them to quantify the process by which space dust the
same stuff that makes up planets and even people is recycled in a
galaxy. The picture shows dust at its three main cosmic hangouts:
around the young stars, where it is being consumed (red-tinted, bright
clouds); scattered about in the space between stars (greenish clouds);
and in expelled shells of material from old stars (randomly-spaced red
dots).

The Large Magellanic Cloud, located 160,000 light-years
from Earth, is one of a handful of dwarf galaxies that orbit our own
Milky Way. It is approximately one-third as wide as the Milky Way, and,
if it could be seen in its entirety, would cover the same amount of sky
as a grid of about 480 full moons. About one-third of the entire galaxy
can be seen in the Spitzer image.

This picture is a composite of
infrared light captured by Spitzer. Light with wavelengths of 3.6
(blue) and 8 (green) microns was captured by the telescope's infrared
array camera; 24-micron light (red) was detected by the multiband
imaging photometer.

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located at IPAC on the campus of the California Institute of Technology.